Antenna apparatus and measurement method

ABSTRACT

An measurement apparatus (antenna apparatus)  1  includes: an OTA chamber  50  having an internal space  51  that is not influenced by the surrounding radio wave environment; a reflector  7  that is housed in the internal space  51 , radio signals transmitted or received by an antenna  110  of a DUT  100  being reflected through a paraboloid of revolution; a plurality of test antennas  6  that use radio signals in a plurality of measurement target frequency bands for measuring the transmission and reception characteristics of the DUT  100 ; and automatic antenna arrangement means  60  for sequentially arranging each of the test antennas  6  at a focal position F, which is determined from the paraboloid of revolution, according to the measurement target frequency bands.

TECHNICAL FIELD

The present invention relates to an antenna apparatus and a measurement method for measuring the transmission and reception characteristics of a device under test using a plurality of measurement antennas using an anechoic box in an over the air (OTA) environment.

BACKGROUND ART

In recent years, with the development of multimedia, wireless terminals (smartphones and the like) in which an antenna for wireless communication, such as cellular and wireless LAN, is mounted are being actively produced. In the future, in particular, there is a demand for a wireless terminal that transmits and receives radio signals corresponding to IEEE 802.11ad, 5G cellular, and the like that use broadband signals in a millimeter wave band.

In a wireless terminal manufacturing plant, a performance test is performed in which the output level or the reception sensitivity of the transmission radio wave defined for each communication standard is measured for a wireless communication antenna provided in a wireless terminal to determine whether or not a predetermined standard is satisfied.

With the transition of generation from 4G or 4G advance to 5G a test method for the performance test described above is also changing. For example, in a performance test in which a wireless terminal for 5G new radio system (NR system) (hereinafter, a 5G wireless terminal) is a device under test (DUT), cable connection between the antenna terminal of the DUT and a testing device, which is a mainstream in tests of 4G 4G advance, and the like, cannot be used. For this reason, a so-called OTA test is performed in which the DUT is housed in a box, which is not influenced by the surrounding radio wave environment, together with a test antenna and transmission of a test signal from the test antenna to the DUT and reception of a measurement target signal from the DUT, which has received the test signal, by the test antenna are performed by wireless communication.

In the performance test of the 5G wireless terminal, a compact antenna test range (hereinafter, a CATR) is known as test equipment for realizing the OTA test environment described above. The CATR includes an anechoic box called an OTA chamber, and houses the DUT and the test antenna so that intrusion of radio waves from the outside and radiation of radio waves to the outside are prevented. In addition, in the CATR, a reflector having a paraboloid of revolution is arranged in the signal propagation path between the antenna of the DUT and the test antenna. Therefore, since the signal propagation path can be shortened compared with a case where no reflector is used, the CATR is characterized in that compactness can be literally realized compared with the OTA test in a general far-field environment.

In a measurement apparatus using the CATR, a test signal is transmitted from the test antenna to be received by the DUT in the OTA chamber, and a measurement target signal transmitted from the DUT that has received the test signal is received by the test antenna and the performance test described above is performed.

On the other hand, the 5G wireless terminal has a wide use frequency range. For this reason, in a case where the 5G wireless terminal cannot be covered by one test antenna at the time of measurement in a state in which the 5G wireless terminal is housed as a DUT in the CATR, it is necessary to prepare a plurality of test antennas that use a plurality of different frequency bands within the usable frequency range.

As a conventional antenna measurement apparatus using a plurality of test antennas, there is known a technique for simultaneously transmitting a plurality of beams with the same frequency, on which different codes are superimposed, through a multi-beam antenna and simultaneously measuring all beams radiated from the multi-beam antenna while suppressing the influence of unnecessary waves due to encoding on the plurality of beams with the same frequency (for example, refer to Patent Document 1).

RELATED ART DOCUMENT Patent Document

[Patent Document 1] JP-A-2009-147687

DISCLOSURE OF THE INVENTION Problem that the Invention is to Solve

In the above-described conventional measurement apparatus using the CATR and the plurality of test antennas, in the case of measuring the transmission and reception characteristics of the DUT for each frequency band used by each test antenna, it is necessary to manually replace the test antennas one by one at the focal position of the reflector in the anechoic box. In this case, it is necessary to secure a place for storing the plurality of test antennas in the anechoic box, and it takes time and effort to take out one test antenna from the place and install the test antenna at the focal position. This causes an increase in the size of the anechoic box. In addition, a complicated work for replacement of the test antenna is required. In addition, in this type of conventional measurement apparatus, since the measurement is unavoidably interrupted at the time of replacement of each test antenna, and the measurement processing also becomes complicated.

In addition, although Patent Document 1 discloses a technique for reflecting radio waves radiated from each antenna forming a multi-beam antenna on a mirror surface and measuring the radio waves and a technique for rotating each antenna, each antenna could not be switched to the focal position of the mirror surface. In addition, Patent Document 1 discloses rotating each antenna merely to change the position of each antenna, but each antenna is not sequentially arranged at the focal position of the mirror surface.

The present invention has been made to solve such conventional problems, and it is an object of the present invention to provide an antenna apparatus and a measurement method capable of efficiently measuring the transmission and reception characteristics for frequency bands corresponding to a plurality of test antennas to be tested while avoiding an increase in the size of an anechoic box and the complication of a work for replacement of the test antennas.

Means for Solving the Problem

In order to solve the aforementioned problem, an antenna apparatus according to a first aspect of the present invention includes: an anechoic box having an internal space that is not influenced by a surrounding radio wave environment; a reflector that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna to be tested of a device under test being reflected through the paraboloid of revolution; a plurality of antennas corresponding to radio signals in a plurality of measurement target frequency bands for measuring transmission and reception characteristics of the device under test; and antenna arrangement means for sequentially arranging the plurality of antennas at a focal position, which is determined from the paraboloid of revolution, according to the measurement target frequency bands.

With this configuration, in the antenna apparatus according to the first aspect of the present invention, since the antenna arrangement means is provided in the anechoic box, the user does not need to perform a work for sequential replacement of the plurality of antennas at the focal position of the reflector during the measurement of the transmission and reception characteristics of a device under test (DUT). In addition, since the antenna arrangement means is added after shortening the signal propagation path by providing the reflector, this is not a major obstacle for the anechoic box to be made compact. In addition, since the measurement of the transmission and reception characteristics of the device under test for each measurement target frequency band can be performed without interruption while reducing the time and effort for arranging each antenna at the focal position, the efficiency of the measurement processing can be improved.

In an antenna apparatus according to a second aspect of the present invention, the antenna to be tested uses a radio signal in a specified frequency band. A simulation measurement apparatus is further provided that, each time one of the plurality of antennas is arranged at the focal position, outputs a test signal to the device under test through the antenna arranged at the focal position, receives a measurement target signal output from the device under test to which the test signal has been input through the antenna arranged at the focal position, and measures transmission and reception characteristics of the device under test for the measurement target frequency band, which is used by the antenna arranged at the focal position, based on the received measurement target signal.

With this configuration, the antenna apparatus according to the second aspect of the present invention can smoothly measure the transmission and reception characteristics of the DUT, which has an antenna to be tested that uses a radio signal in a specified frequency band, without much time and effort for replacement of the test antenna for frequency bands of a plurality of different frequency band groups in the specified frequency band.

In an antenna apparatus according to a third aspect of the present invention, the specified frequency band is a 5G NR band, and each of the plurality of measurement target frequency bands is a frequency band of any one of frequency band groups of a group of n77, n78, and n79, a group of n258 and n257, and a group of n259 that are a plurality of different frequency band groups in the specified frequency band.

With this configuration, the antenna apparatus according to the third aspect of the present invention can smoothly measure the transmission and reception characteristics of the DUT (5G wireless terminal), which has an antenna to be tested that uses a radio signal in the 5G NR band, without much time and effort for replacement of the test antenna for a frequency band of any one of frequency band groups of a group of n77, n78, and n79, a group of n258 and n257, and a group of n259.

In an antenna apparatus according to a fourth aspect of the present invention, the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.

With this configuration, since the antenna apparatus according to the fourth aspect of the present invention adopts the antenna holding mechanism in which each antenna is arranged on the circumference around the rotary shaft for the rotating body rotatable with the rotary shaft as the center, it is possible to reduce the installation space of the antenna holding mechanism while keeping the anechoic box compact.

In an antenna apparatus according to a fifth aspect of the present invention, the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a horizontal direction by the rotary shaft along a vertical direction.

With this configuration, in the antenna apparatus according to the fifth aspect of the present invention, a space horizontal to the bottom surface of the internal space of the anechoic box is secured as an installation space of the antenna holding mechanism. Therefore, it is possible to prevent an increase in the height of the anechoic box.

In an antenna apparatus according to a sixth aspect of the present invention, the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.

With this configuration, in the antenna apparatus according to the sixth aspect of the present invention, the antenna holding mechanism is arranged at the central portion of the bottom surface of the internal space of the anechoic box. Therefore, since the diameter of the circumference on which each antenna is arranged can be reduced, it is possible to keep the antenna holding mechanism and the anechoic box compact.

In an antenna apparatus according to a seventh aspect of the present invention, the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.

With this configuration, in the antenna apparatus according to the seventh aspect of the present invention, the antenna holding mechanism is arranged at a position near the side surface avoiding the central portion of the bottom surface of the internal space of the anechoic box. Therefore, since the diameter of the circumference on which each antenna is arranged can be reduced, it is possible to keep the antenna holding mechanism and the anechoic box compact.

In an antenna apparatus according to an eighth aspect of the present invention, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.

With this configuration, in the antenna apparatus according to the eighth aspect of the present invention, it is possible to improve the reception accuracy of each antenna arranged at the focal position of the reflector and improve the measurement accuracy of the transmission and reception characteristics of the DUT.

In an antenna apparatus according to a ninth aspect of the present invention, the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a vertical direction by the rotary shaft along a horizontal direction.

With this configuration, in the antenna apparatus according to the ninth aspect of the present invention, a space perpendicular to the bottom surface of the internal space of the anechoic box is secured as an installation space of the antenna holding mechanism. Therefore, it is possible to prevent an increase in the width of the anechoic box.

In an antenna apparatus according to a tenth aspect of the present invention, the antenna arrangement means includes: an antenna holding mechanism that has a first slide mechanism that holds a plurality of antenna pedestals, on which the antennas are provided, so as to be slidable in one direction while maintaining a predetermined interval and a second slide mechanism that slidably holds the first slide mechanism in the other direction perpendicular to the one direction through a pedestal portion and that is provided in the internal space of the anechoic box such that each of the antennas is able to pass through the focal position; a power unit that includes a first driving motor for rotationally driving a first driving shaft for sliding each of the antenna pedestals in the one direction and a second driving motor for rotationally driving a second driving shaft for sliding the pedestal portion in the other direction; and an automatic antenna arrangement control unit that controls the first and second driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.

With this configuration, in the antenna apparatus according to the tenth aspect of the present invention, a space horizontal to the bottom surface of the internal space of the anechoic box is secured as an installation space of the antenna holding mechanism. Therefore, it is possible to prevent an increase in the height of the anechoic box. In addition, since the antennas slide in directions perpendicular to each other on the horizontal plane, stable movement toward the focal position is possible.

In an antenna apparatus according to an eleventh aspect of the present invention, a plurality of the first slide mechanisms are provided so as to be parallel to the one direction and be spaced apart from each other by a predetermined distance in the other direction, and the power unit includes the first driving motor corresponding to each of the first slide mechanisms.

With this configuration, the antenna apparatus according to the eleventh aspect of the present invention can easily cope with the addition of each antenna while avoiding an increase in the size of the anechoic box by making full use of the space in the horizontal direction on the bottom surface of the anechoic box.

In an antenna apparatus according to a twelfth aspect of the present invention, the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.

In an antenna apparatus according to a thirteenth aspect of the present invention, the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.

In an antenna apparatus according to a fourteenth aspect of the present invention, the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.

In an antenna apparatus according to a fifteenth aspect of the present invention, the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.

In an antenna apparatus according to a sixteenth aspect of the present invention, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.

In an antenna apparatus according to a seventeenth aspect of the present invention, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.

In an antenna apparatus according to an eighteenth aspect of the present invention, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.

In an antenna apparatus according to a nineteenth aspect of the present invention, the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a vertical direction by the rotary shaft along a horizontal direction.

A measurement method according to a twentieth aspect of the present invention is a measurement method using the antenna apparatus according to any one of the first to nineteenth aspects, and includes: a holding step of holding the device under test in a device under test holding unit in the anechoic box; an antenna arrangement step of sequentially arranging the plurality of antennas at the focal position according to the measurement target frequency bands based on a predetermined measurement start command; a test signal output step of causing the simulation measurement device to output a test signal to the device under test through the antenna arranged at the focal position; a signal receiving step of receiving a measurement target signal, which is output from the device under test to which the test signal has been input, through the antenna arranged at the focal position; and a measurement step of measuring transmission and reception characteristics of the device under test for a radio signal in the measurement target frequency band, which is used by the antenna arranged at the focal position, based on the measurement target signal received in the signal receiving step.

With this configuration, since the measurement method according to the twentieth aspect of the present invention uses the antenna apparatus having an anechoic box in which antenna arrangement means is provided, the user does not need to perform a work for sequential replacement of the plurality of antennas at the focal position of the reflector during the measurement of the transmission and reception characteristics of the device under test. In addition, since the antenna arrangement means is added after shortening the signal propagation path by providing the reflector, this is not a major obstacle for the anechoic box to be made compact. In addition, since the measurement of the transmission and reception characteristics of the device under test for each measurement target frequency band can be performed without interruption while reducing the time and effort for arranging each antenna, the efficiency of the measurement processing can be improved.

[Advantage of the Invention]

The present invention can provide an antenna apparatus and a measurement method capable of efficiently measuring the transmission and reception characteristics for frequency bands corresponding to a plurality of test antennas to be tested while avoiding an increase in the size of an anechoic box and the complication of a work for replacement of the test antennas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the schematic configuration of the entire measurement apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing the functional configuration of the measurement apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing the functional configuration of an integrated control device of the measurement apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing the functional configuration of an NR system simulator in the measurement apparatus according to the first embodiment of the present invention.

FIGS. 5A and 5B are schematic diagrams illustrating a near field and a far field in radio wave propagation between an antenna AT and a wireless terminal.

FIG. 6 is a schematic diagram showing the signal path structure of a parabola having the same paraboloid of revolution as a reflector adopted in an OTA chamber of the measurement apparatus according to the first embodiment of the present invention.

FIG. 7 is a schematic diagram showing the signal path structure of an offset parabola having the same paraboloid of revolution as a reflector adopted in an OTA chamber of the measurement apparatus according to the first embodiment of the present invention.

FIG. 8 is a table showing the use frequency classification of a plurality of test antennas for measurement of the transmission and reception characteristics of a DUT adopted in an OTA chamber of the measurement apparatus according to the first embodiment of the present invention.

FIGS. 9A and 9B are conceptual diagrams showing the arrangement of test antennas in automatic antenna arrangement means of the measurement apparatus according to the first embodiment of the present invention.

FIG. 10 is a flowchart showing a process of measuring the transmission and reception characteristics of a DUT in the measurement apparatus according to the first embodiment of the present invention.

FIG. 11 is a side view showing the schematic configuration of automatic antenna arrangement means adopted in an OTA chamber of a measurement apparatus according to a second embodiment of the present invention.

FIGS. 12A and 12B are schematic configuration diagrams of automatic antenna arrangement means adopted in an OTA chamber of a measurement apparatus according to a third embodiment of the present invention.

FIG. 13 is a perspective view showing the schematic configuration of automatic antenna arrangement means adopted in an OTA chamber of a measurement apparatus according to a fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a measurement apparatus and a measurement method according to the present invention will be described with reference to the diagrams.

First Embodiment

First, the configuration of a measurement apparatus 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 9. The measurement apparatus 1 corresponds to an antenna apparatus of the present invention. The measurement apparatus 1 according to the present embodiment has an appearance structure shown in FIG. 1 as a whole, and is configured by functional blocks as shown in FIG. 2. FIG. 1 shows the arrangement of components in a state in which an OTA chamber 50 is seen through from the side surface.

As shown in FIGS. 1 and 2, the measurement apparatus 1 according to the present embodiment has an integrated control device 10, an NR system simulator 20, a signal processing unit 40, and the OTA chamber 50.

The integrated control device 10 is communicably connected to the NR system simulator 20 through a network 19, such as Ethernet (registered trademark). In addition, the integrated control device 10 is also connected to control target elements in the OTA chamber 50 through the network 19. The measurement apparatus 1 has an automatic antenna arrangement control unit 16 and a DUT posture control unit 17 as control target elements in the OTA chamber 50.

The integrated control device 10 performs overall control of control target elements in the NR system simulator 20 and the OTA chamber 50 through the network 19, and is, for example, a personal computer (PC). The automatic antenna arrangement control unit 16 and the DUT posture control unit 17 may be provided in the integrated control device 10, for example, as shown in FIG. 3. The following explanation will be given on the assumption that the integrated control device 10 has a configuration shown in FIG. 3.

The measurement apparatus 1 is operated, for example, in a state in which each component is mounted on each rack 90 a using a rack structure 90 having a plurality of racks 90 a shown in FIG. 1. In FIG. 1, an example is mentioned in which the integrated control device 10, the NR system simulator 20, and the OTA chamber 50 are mounted on each rack 90 a of the rack structure 90.

Here, for the sake of convenience, the configuration of the OTA chamber 50 will be described first. The OTA chamber 50 realizes an OTA test environment in testing the performance of a 5G wireless terminal, and is used as an example of the CATR described above.

As shown in FIGS. 1 and 2, for example, the OTA chamber 50 is formed by a metal housing main body 52 having a rectangular parallelepiped internal space 51. In the internal space 51, a DUT 100 and a plurality of test antennas 6 that can face an antenna 110 of the DUT 100 are housed so that intrusion of radio waves from the outside and radiation of radio waves to the outside are prevented. In the internal space 51 of the OTA chamber 50, the reflector 7 for realizing a radio wave path for returning the radio signal radiated from the antenna 110 of the DUT 100 to the light receiving surface of the test antenna 6 is arranged. A plurality of test antennas 6 configures a plurality of antennas in the present invention. In addition, a radio wave absorber 55 is bonded to the entire inner surface of the OTA chamber 50, that is, the entire bottom surface 52 a, side surface 52 b, and upper surface 52 c of the housing main body 52, so that a function of restricting the radiation of radio waves to the outside is strengthened. Thus, the OTA chamber 50 realizes an anechoic box having the internal space 51 that is not influenced by surrounding radio wave environment. The anechoic box used in the present embodiment is of an anechoic type, for example.

The DUT 100 to be tested is, for example, a wireless terminal such as a smartphone. As a communication standard of the DUT 100, cellular (LTE, LTE-A, W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, 1×EV-DO, TD-SCDMA, and the like), wireless LAN (IEEE 802.11b/g/a/n/ac/ad and the like), Bluetooth (registered trademark), GNSS (GPS, Galileo, GLONASS, BeiDou, and the like), FM, and digital broadcasting (DVB-H, ISDB-T, and the like) can be mentioned. In addition, the DUT 100 may also be a wireless terminal that transmits and receives radio signals in a millimeter wave band corresponding to IEEE 802.11ad, 5G cellular, and the like.

In the present embodiment, the DUT 100 is a 5G NR wireless terminal. For the 5G NR wireless terminal, the 5G NR standard specifies that a predetermined frequency band (refer to “5G NR band” in FIG. 8) including the millimeter wave band and other frequency bands used in LTE and the like is a communicable frequency range. In short, the antenna 110 of the DUT 100 uses a radio signal in a predetermined frequency band (5G NR band). The antenna 110 of the DUT 100 corresponds to an antenna to be tested in the present invention.

The 5G NR wireless terminal having the communicable frequency range described above is set to be able to communicate using any one of the bands identified by the numbers 1, 2, and 3 in the table shown in FIG. 8, for example, at the time of shipment, and thereafter, the usable frequency band can be switched by a predetermined setting change operation. In such a wireless terminal, a band set to be usable may be referred to as an in-band, and a band that is not set to be usable may be referred to as an out-band. In the case of measuring the transmission and reception characteristics in the OTA environment in the OTA chamber 50 using the wireless terminal as the DUT 100, measurement is required for all the bands of the in-band and the out-band described above.

FIG. 8 is a table showing the usable frequency range classification of the three test antennas 6 arranged in the OTA chamber 50 according to the present embodiment. As shown in FIG. 8, three frequency bands identified by the numbers 1, 2, and 3 are assigned to 3.3 MHz to 5.0 MHz, 24.25 MHz to 40.0 MHz, and 40.5 MHz to 43.5 MHz, respectively. The frequency bandwidth (3.3 MHz to 5.0 MHz) assigned to the number 1 corresponds to a group of frequency bandwidths (frequency band group) including, for example, frequency bands of n77, n78, and n79 in the known 5G NR band list defined by 3rd generation partnership project (3GPP). Similarly, the frequency bandwidth of 24.25 MHz to 29.5 MHz assigned to the number 2 and the frequency bandwidth of 40.5 MHz to 43.5 MHz assigned to the number 3 correspond to a group of frequency bandwidths including frequency bands of n258 and n260 and a group of frequency bandwidths including a frequency band of n259 defined in the band list, respectively, for example.

In the present embodiment, in the OTA chamber 50, for example, three test antennas 6 using frequency bands corresponding to the numbers 1, 2, and 3 in the frequency band classification shown in FIG. 8 are arranged in the internal space 51. The three test antennas 6 are automatically arranged one by one in order at the focal position (indicated by reference symbol F in FIG. 1) of the reflector 7 by the automatic antenna arrangement means 60. On the other hand, the DUT 100 according to the present embodiment is configured to be able to selectively set the frequency bands corresponding to the numbers 1, 2, and 3 as usable frequency bands. During measurement regarding transmission and reception in the OTA chamber 50, the DUT 100 can transmit and receive a test signal and a measurement target signal through the test antennas 6 sequentially arranged at the focal position F using the frequency bands corresponding to the numbers 1, 2, and 3 in order.

Next, the arrangement of the DUT holding unit 56, the test antenna 6, and the reflector 7 in the internal space 51 of the OTA chamber 50 will be described. In the OTA chamber 50, a DUT holding unit 56 extending in a vertical direction is provided on the bottom surface 52 a of the housing main body 52 in the internal space 51. The DUT holding unit 56 has a driving unit 56 a provided on the bottom surface 52 a, a support stand 56 b connected to the driving unit 56 a, and a DUT mounting unit 56 c extending in a horizontal direction from the side surface of the support stand 56 b. The driving unit 56 a is formed by, for example, a two-axis positioner including a rotation mechanism that rotates in two axial directions. Hereinafter, the driving unit 56 a may be referred to as a two-axis positioner (refer to FIG. 3). Therefore, the DUT holding unit 56 can rotate the DUT 100 held by the DUT mounting unit 56 c so as to be located at the center of the sphere and to be able to sequentially change the posture to a state in which the antenna 110 is directed to all points on the surface of the sphere, for example.

In the OTA chamber 50, the antenna holding mechanism 61 is provided at a position below the bottom surface 52 a of the housing main body 52, and the antenna holding mechanism 61 holds the plurality of test antennas 6 in a state in which the plurality of test antennas 6 are spaced apart from each other. In the present embodiment, the antenna holding mechanism 61 holds the three test antennas 6 capable of transmitting and receiving radio signals in the three measurement target frequency bands identified by the numbers 1 to 3 in the table shown in FIG. 8, for example.

The antenna holding mechanism 61 is attached to the bottom surface 52 a in the internal space 51 of the OTA chamber 50 through a power unit 64. The antenna holding mechanism 61 forms automatic antenna arrangement means 60 together with the power unit 64 and the automatic antenna arrangement control unit 16 (refer to FIG. 2). The automatic antenna arrangement means 60 forms antenna arrangement means of the present invention. The configuration of the automatic antenna arrangement means 60 will be described in detail later.

In the OTA chamber 50, the reflector 7 has an offset parabola (refer to FIG. 7) type structure to be described later. As shown in FIG. 1, the reflector 7 is attached to a required position of the side surface 52 b of the OTA chamber 50 using a reflector holder 58. The reflector 7 is arranged at a position and posture at which a test signal radiated from one test antenna 6 arranged at the focal position F of the paraboloid of revolution can be received on the paraboloid of revolution and reflected toward the DUT 100 held by the DUT holding unit 56 and the DUT 100 having received the test signal can receive a measurement target signal radiated from the antenna 110 on the paraboloid of revolution and reflect the measurement target signal toward the test antenna 6 from which the test signal has been radiated. In the present embodiment, as the test antenna 6 for transmitting and receiving the test signal and the measurement target signal described above, three test antennas 6 held by the antenna holding mechanism 61 are automatically arranged at the focal position F one by one in order by the automatic antenna arrangement means 60.

Here, the merit of mounting the reflector 7 in the OTA chamber 50 and the preferable form of the reflector 7 will be described with reference to FIGS. 5A to 7. FIGS. 5A and 5B are schematic diagrams showing how radio waves radiated from an antenna AT equivalent to the test antenna 6 are transmitted to a wireless terminal 100A, for example. The wireless terminal 100A corresponds to the DUT 100. FIG. 5A shows an example of a case where radio waves are directly transmitted from the antenna AT to the wireless terminal 100A (Direct FAR Field), and FIG. 5B shows an example of a case where radio waves are transmitted from the antenna AT to the wireless terminal 100A through a reflecting mirror 7A having a paraboloid of revolution.

As shown in FIG. 5A, a radio wave having the antenna AT as a radiation source has a feature that the radio wave propagates while the wavefront spreads spherically with the radiation source at the center. In addition, it is known that a surface (wavefront) obtained by connecting the in-phase points of the waves is a curved spherical surface (spherical wave) at a short distance from the radiation source, but the wavefront becomes close to a plane (plane wave) as the distance from the radiation source increases. In general, a region where the wavefront needs to be considered as a spherical surface is called a near field (NEAR FIELD), and a region where the wavefront may be considered as a plane is called a far field (FAR FIELD). In the propagation of radio waves shown in FIG. 5A, it is preferable that the wireless terminal 100A receives a plane wave rather than receiving a spherical wave in order to perform satisfactory reception.

In order to receive a plane wave, the wireless terminal 100A needs to be provided so as to exist in the far field. Here, assuming that the maximum linear size of the wireless terminal 100A is D and the wavelength is λ, the far field is a distance of 2D²/λ, or more from the antenna AT. Specifically, in the case of D=0.4 meters (m) and wavelength λ=0.01 m (corresponding to a radio signal in a 28 GHz band), the position of approximately 30 m from the antenna AT is a boundary between the near field and the far field, and it is necessary to place the wireless terminal 100A at a position farther from the boundary. In the present embodiment, measurement of the DUT 100 whose maximum linear size D is, for example, about 5 cm (centimeters) to about 33 cm is assumed.

Thus, the Direct Far Field method shown in FIG. 5A has a feature that the propagation distance between the antenna AT and the wireless terminal 100A is large and the propagation loss is large. Therefore, as a countermeasure, for example, as shown in FIG. 5B, there is a method in which the reflecting mirror 7A having a paraboloid of revolution is arranged at a position where the radio wave of the antenna AT can be reflected and introduced by the wireless terminal 100A. According to this method, not only can the distance between the antenna AT and the wireless terminal 100A be shortened, but also the region of the plane wave spreads from the distance immediately after reflection on the mirror surface of the reflecting mirror 7A. Therefore, the reduction effect of the propagation loss can also be expected. The propagation loss can be expressed by the phase difference between the waves in phase. The phase difference that can be allowed as a propagation loss is, for example, λ/16. The phase difference is assumed to be evaluated by, for example, a vector network analyzer (VNA).

For example, a parabola (refer to FIG. 6) or an offset parabola (refer to FIG. 7) can be used as the reflecting mirror 7A shown in FIG. 5A. As shown in FIG. 6, the parabola has a mirror surface (paraboloid of revolution) that is symmetrical with respect to the axis passing through the antenna center O. By providing a primary radiator, which has directivity in the direction of the paraboloid of revolution, at the focal position F determined from the paraboloid of revolution, the parabola has a function of reflecting radio waves radiated from the primary radiator in a direction parallel to the axial direction. On the contrary, it can be understood that, by arranging, for example, the test antenna 6 according to the present embodiment at the focal position F, the parabola can reflect radio waves (for example, radio signal transmitted from the DUT 100) incident on the paraboloid of revolution in a direction parallel to the axial direction so that the radio waves are guided to the test antenna 6. However, since the planar shape of the parabola viewed from the front (Z direction) is a perfect circle, the structure is large. For this reason, the parabola is not suitable for being arranged as the reflector 7 of the OTA chamber 50.

On the other hand, as shown in FIG. 7, the offset parabola has a mirror surface that is asymmetric with respect to the axis of the paraboloid of revolution (a shape obtained by cutting out a part of the paraboloid of revolution of the perfect circle type parabola (refer to FIG. 6)). By providing a primary radiator with its beam axis inclined at an angle α, for example, with respect to the axis of the paraboloid of revolution, the offset parabola has a function of reflecting radio waves radiated from the primary radiator in a direction parallel to the axial direction of the paraboloid of revolution. It can be understood that, by arranging, for example, the test antenna 6 according to the present embodiment at the focal position F, the offset parabola can reflect radio waves (for example, a test signal with respect to the DUT 100) radiated from the test antenna 6 on the paraboloid of revolution in a direction parallel to the axial direction of the paraboloid of revolution and reflect radio waves (for example, a measurement target signal transmitted from the DUT 100) incident on the paraboloid of revolution in a direction parallel to the axial direction of the paraboloid of revolution so that the radio waves are guided to the test antenna 6. Since the offset parabola can be arranged such that the mirror surface is almost vertical, the structure is much smaller than the parabola (refer to FIG. 6).

Based on the findings described above, in the OTA chamber 50 according to the present embodiment, as shown in FIG. 1, the reflector 7 using the offset parabola (refer to FIG. 7) is arranged in the radio wave propagation path between the DUT 100 and the test antenna 6. The reflector 7 is attached to the side surface 52 b of the housing main body 52 so that the position indicated by the reference numeral F in the diagram is the focal position.

The reflector 7 and one (arranged at the focal position) of the three test antennas 6 held by the antenna holding mechanism 61 are in an offset state in which the beam axis BS1 of the test antenna 6 is inclined by a predetermined angle α with respect to the axis RS1 of the reflector 7. One test antenna 6 referred to herein is the test antenna 6 that can be viewed from the reflector 7 through an opening 67 a of a cover unit 67 that covers the antenna holding mechanism 61.

The reflector 7 has the focal position F on the beam axis BS1 of the test antenna 6, and each test antenna 6 held by a rotating body 62 of the antenna holding mechanism 61 can sequentially pass through the position of one test antenna 6 whose visibility can be secured as described above, that is, the focal position F of the reflector 7. The inclination angle α described above can be set to, for example, 30°. In this case, the test antenna 6 is held by the antenna holding mechanism 61 so as to face the reflector 7 at an elevation angle of 30°, that is, so as to face the reflector 7 at an angle at which the receiving surface of the test antenna 6 is perpendicular to the beam axis of the radio signal. By adopting the offset parabola type reflector 7, the reflector 7 itself can be made small. Therefore, since it is possible to arrange the reflector 7 in such a posture that the mirror surface is almost vertical, there is a merit that the structure of the OTA chamber 50 can be reduced.

Next, the configuration of the automatic antenna arrangement means 60 for sequentially arranging a plurality of test antennas 6 at the focal position F of the reflector 7 will be described in detail.

The automatic antenna arrangement means 60 mounted in the OTA chamber 50 has the antenna holding mechanism 61, the power unit 64, the cover unit 67, and the automatic antenna arrangement control unit 16, for example, as shown in FIGS. 1 and 2. The antenna holding mechanism 61 is formed by the rotating body 62 that can rotate around a rotary shaft 63. In the rotating body 62, for example, three test antennas 6 are arranged on the circumference around the rotary shaft 63.

As a more specific example, for example, as shown in FIG. 9A, in the rotating body 62, the three test antennas 6 are arranged at equal intervals along the outer periphery of a circle Cl defining the circumference described above, that is, at intervals of 120° around the rotary shaft 63 on the horizontal plane. Here, the antenna holding mechanism 61 is provided in the internal space 51 so that the receiving surface of each test antenna 6, which moves (rotates) in the circumferential direction on the circumference of the circle Cl by rotation of the rotating body 62, passes through the focal position F of the reflector 7. The three test antennas 6 used in the present embodiment can transmit and receive radio signals in respective frequency bands identified by the numbers 1 to 3 in the table shown in FIG. 8, for example. The arrangement of the three test antennas 6 on the circumference is not limited to the arrangement (number and separation angle) shown in FIG. 9A. For example, as shown in FIG. 9B, the three test antennas 6 may be arranged so as to be close to each other at intervals of 60° with the rotary shaft 63 as the center. In the present invention, it is needless to say that the number of test antennas 6 is not limited to three mentioned in the present embodiment and can be set to any number according to the allocation of in-bands and out-bands of the DUT 100 (refer to FIG. 13).

The power unit 64 has a driving motor 65 for rotationally driving the rotating body 62 through the rotary shaft 63 and a connection member 66 such as a gear arranged between the driving motor 65 and the rotary shaft 63. The cover unit 67 covers the antenna holding mechanism 61 and the power unit 64 so that intrusion of radio waves from the outside and radiation of radio waves to the outside can be restricted.

The opening 67 a is formed in the cover unit 67. The opening 67 a is formed at a position, at which a view from the test antenna 6 with respect to the paraboloid of revolution of the reflector 7 can be secured, in a case where one of the test antennas 6 held by the antenna holding mechanism 61 is arranged at the focal position F of the reflector 7.

The automatic antenna arrangement control unit 16 drives the driving motor 65 based on a command from a control unit 11 (refer to FIG. 3) of the integrated control device 10 so that each test antenna 6 moves to the focal position F of the reflector 7 and stops in a sequential manner according to each measurement target frequency band identified by the numbers 1 to 3 in the table shown in FIG. 8, for example.

Here, the functional configuration of the measurement apparatus 1 according to the present embodiment will be described in more detail with reference to FIGS. 2 to 4. In the measurement apparatus 1 (refer to FIG. 2) according to the present embodiment, the integrated control device 10 has, for example, a functional configuration shown in FIG. 3, and the NR system simulator 20 has, for example, a functional configuration shown in FIG. 4. The NR system simulator 20 forms a simulation measurement device of the present invention.

As shown in FIG. 3, the integrated control device 10 has the control unit 11, an operation unit 12, and a display unit 13. The control unit 11 is, for example, a computer apparatus. For example, as shown in FIG. 3, the computer apparatus has: a central processing unit (CPU) 11 a that performs predetermined information processing for realizing the function of the measurement apparatus 1 or overall control of the NR system simulator 20; a read only memory (ROM) 11 b that stores an operating system (OS) for starting the CPU 11 a or other programs, control parameters, and the like; a random access memory (RAM) 11 c that stores the execution code, data, and the like of the OS or applications that the CPU 11 a uses for operation; an external interface (I/F) unit 11 d having an input interface function for receiving a predetermined signal and an output interface function for outputting a predetermined signal; a non-volatile storage medium such as a hard disk drive (not shown); and various input and output ports. The external I/F unit 11 d is communicably connected to the NR system simulator 20 through the network 19. In addition, the external I/F unit 11 d is also connected to the driving motor 65 and the driving unit (two-axis positioner) 56 a in the OTA chamber 50 through the network 19. The operation unit 12 and the display unit 13 are connected to the input and output ports. The operation unit 12 is a functional unit that inputs various kinds of information, such as commands, and the display unit 13 is a functional unit that displays various kinds of information, such as an input screen for the various kinds of information and measurement results.

The computer apparatus described above functions as a control unit 11 by the CPU 11 a that executes a program stored in the ROM 11 b using the RAM 11 c as a work area. As shown in FIG. 3, the control unit 11 has a call connection control unit 14, a signal transmission and reception control unit 15, the automatic antenna arrangement control unit 16, and the DUT posture control unit 17. The call connection control unit 14, the signal transmission and reception control unit 15, the automatic antenna arrangement control unit 16, and the DUT posture control unit 17 are also realized by the CPU 11 a that executes a predetermined program stored in the ROM 11 b using the RAM 11 c as a work area.

The call connection control unit 14 performs control to establish a call (a state in which radio signals can be transmitted and received) between the NR system simulator 20 and the DUT 100 by driving the test antenna 6, which is automatically arranged at the focal position F of the reflector 7, to transmit and receive a control signal (radio signal) to and from the DUT 100.

The signal transmission and reception control unit 15 monitors a user operation in the operation unit 12. In response to a predetermined measurement start operation for the measurement of the transmission and reception characteristics of the DUT 100 by the user, through the call connection control of the call connection control unit 14, the signal transmission and reception control unit 15 performs control to transmit a signal transmission command to the NR system simulator 20 and transmit a test signal through the test antenna 6, and performs control to transmit a signal reception command and receive a measurement target signal through the test antenna 6.

The automatic antenna arrangement control unit 16 performs control to automatically arrange the plurality of test antennas 6, which are held by the antenna holding mechanism 61 of the automatic antenna arrangement means 60, at the focal position F of the reflector 7 in a sequential manner. In order to realize this control, for example, an automatic antenna arrangement control table 16 a is stored in the ROM 11 b in advance. For example, in a case where a stepping motor is adopted as the driving motor 65, the automatic antenna arrangement control table 16 a stores the number of driving pulses (the number of operation pulses) for determining the rotational driving of the stepping motor as control data. In the present embodiment, the automatic antenna arrangement control table 16 a stores, as the control data, the number of operation pulses of the driving motor 65 for moving each test antenna 6 to the focal position F of the reflector 7 corresponding to, for example, each of the three measurement target frequency bands identified by the numbers 1 to 3 shown in FIG. 8.

The automatic antenna arrangement control unit 16 expands the automatic antenna arrangement control table 16 a to the work area of the RAM 11 c, and performs control for rotationally driving the driving motor 65 in the power unit 64 of the automatic antenna arrangement means 60 according to the measurement target frequency band corresponding to each test antenna 6 based on the automatic antenna arrangement control table 16 a. By this control, it is possible to realize automatic antenna arrangement control to stop (arrange) each test antenna 6 at the focal position F of the reflector 7 in a sequential manner. In the present embodiment, an example has been mentioned in which the automatic antenna arrangement control unit 16 rotationally drives the driving motor 65 so that the test antenna 6 rotates in one direction (refer to FIGS. 1 and 9). However, the present invention is not limited thereto, and the automatic antenna arrangement control unit 16 may rotationally drive the driving motor 65 so that the test antenna 6 rotates in the reverse direction or in both directions. This point is the same as in the second and third embodiments.

The DUT posture control unit 17 controls the posture of the DUT 100 held by the DUT holding unit 56 during measurement. In order to realize this control, for example, a DUT posture control table 17 a is stored in the ROM 11 b in advance. The DUT posture control table 17 a stores, for example, control data of the two-axis positioner 56 a that forms the DUT holding unit 56.

The DUT posture control unit 17 expands the DUT posture control table 17 a to the work area of the RAM 11 c, and controls the driving of the two-axis positioner 56 a, based on the DUT posture control table 17 a, to change the posture of the DUT 100 so that the antenna 110 is sequentially directed to all points on the surface of the sphere.

In the measurement apparatus 1 according to the present embodiment, example, as shown in FIG. 4, the NR system simulator 20 has a signal measurement unit 21, a control unit 22, an operation unit 23, and a display unit 24. The signal measurement unit 21 has a signal generation function unit, which is formed by a signal generation unit 21 a, a digital to analog converter (DAC) 21 b, a modulation unit 21 c, and a transmission unit 21 e of an RF unit 21 d, and a signal analysis function unit, which is formed by a reception unit 21 f of the RF unit 21 d, an analog/digital converter (ADC) 21 g, and an analysis processing unit 21 h.

In the signal generation function unit of the signal measurement unit 21, the signal generation unit 21 a generates waveform data having a reference waveform, specifically, an I component baseband signal and a Q component baseband signal that is a quadrature component signal of the I component baseband signal, for example. The DAC 21 b converts the waveform data (the I component baseband signal and the Q component baseband signal) having a reference waveform output from the signal generation unit 21 a from a digital signal to an analog signal, and outputs the analog signal to the modulation unit 21 c. The modulation unit 21 c mixes each of the I component baseband signal and the Q component baseband signal with a local signal, and performs modulation processing for combining both the signals and outputting the result as a frequency of digital modulation. The RF unit 21 d generates a test signal in which the frequency of digital modulation output from the modulation unit 21 c corresponds to the frequency of each communication standard, and the generated test signal is output to the DUT 100 by the transmission unit 21 e.

In the signal analysis function unit of the signal measurement unit 21, the RF unit 21 d receives a measurement target signal, which is transmitted from the DUT 100 that has received the above-described test signal through the antenna 110, using the reception unit 21 f and then mixes the measurement target signal with a local signal to perform conversion into an intermediate frequency band (IF signal). The ADC 21 g converts the measurement target signal, which has been converted into the IF signal by the reception unit 21 f of the RF unit 21 d, from an analog signal to a digital signal, and outputs the digital signal to the analysis processing unit 21 h.

The analysis processing unit 21 h generates waveform data corresponding to the I component baseband signal and the Q component baseband signal by performing digital processing on the measurement target signal output from the ADC 21 g, and then performs processing for analyzing the I component baseband signal and the Q component baseband signal based on the waveform data.

Similarly to the control unit 11 of the integrated control device 10 described above, the control unit 22 is, for example, a computer apparatus including a CPU, a RAM, a ROM, and various input and output interfaces. The CPU performs predetermined information processing and control for realizing each function of the signal generation function unit, the signal analysis function unit, the operation unit 23, and the display unit 24.

The operation unit 23 and the display unit 24 are connected to the input and output interfaces of the computer apparatus described above. The operation unit 23 is a functional unit that inputs various kinds of information, such as commands, and the display unit 24 is a functional unit that displays various kinds of information, such as an input screen for the various kinds of information and measurement results.

Next, processing for measuring the transmission and reception characteristics of the DUT 100 using the measurement apparatus 1 according to the present embodiment will be described with reference to FIG. 10. In FIG. 10, in particular, it is assumed that the three test antennas 6 capable of using the respective frequency bands indicated by the numbers 1, 2, and 3 in the 5G NR band (refer to FIG. 8) are sequentially arranged at the focal position F to measure the DUT 100. In the following description, it is assumed that the frequency band indicated by the number 1 is referred to as an in-band, the frequency band indicated by the number 2 is referred to as out-band 1, and the frequency band indicated by the number 3 is referred to as out-band 2.

In addition, in FIG. 10, a case will be described in which a measurement start operation for giving an instruction to start the process of measuring the transmission and reception characteristics of the DUT 100 is performed by the operation unit 12 of the integrated control device 10. The measurement start operation may also be performed by the operation unit 23 of the NR system simulator 20.

In the measurement apparatus 1, in order to measure the transmission and reception characteristics of the DUT 100, the DUT 100 needs to be set in the internal space 51 of the OTA chamber 50 first. Therefore, in the measurement apparatus 1, a work for setting the DUT 100 to be tested on the DUT mounting unit 56 c of the DUT holding unit 56 of the OTA chamber 50 is performed as the first processing by the user (step S1). In this case, for the automatic antenna arrangement means 60, a plurality of test antennas 3 (in this example, three test antennas 6), by which three measurement target frequency band can be covered, need to be held by the antenna holding mechanism 61, and the antenna holding mechanism 61 needs to be provided at a position where each test antenna 6 can pass through the focal position F (refer to FIG. 7) of the reflector 7 in a sequential manner.

After the work for setting the DUT 100 is performed, for example, the automatic antenna arrangement control unit 16 in the integrated control device 10 monitors whether or not an operation to start the measurement of the transmission and reception characteristics of the DUT 100 has been performed through the operation unit 12 (step S2).

Here, in a case where it is determined that the measurement start operation has not been performed (NO in step S2), the automatic antenna arrangement control unit 16 continues monitoring in step S1 described above. On the other hand, in a case where it is determined that the measurement start operation has been performed (YES in step S2), the automatic antenna arrangement control unit 16 sets n indicating the measurement order of the measurement target frequency band to n=1 indicating the first measurement target frequency band (step S3). In this example, the maximum value of n is 3.

Then, the automatic antenna arrangement control unit 16 performs control to automatically move (arrange) the test antenna 6, which corresponds to the first measurement target frequency band corresponding to n=1, to the focal position F of the reflector 7 (step S4). In this case, the automatic antenna arrangement control unit 16 reads the number of operation pulses of the test antenna 6 corresponding to the first measurement target frequency band (in-band) corresponding to n=1 from the automatic antenna arrangement control table 16 a, and controls the rotation of the driving motor 65 based on the number of operation pulses.

After the end of the automatic arrangement of the reflector 7 of the test antenna 6 corresponding to the first measurement target frequency band to the focal position F by the rotation control described above, the call connection control unit 14 of the control unit 11 performs call connection control by transmitting and receiving a control signal (radio signal) to and from the DUT 100 using the test antenna 6 whose automatic arrangement has been completed (step S5). Here, the NR system simulator 20 performs call connection control to wirelessly transmit a control signal (call connection request signal) having a frequency in a first transmission and reception measurement target frequency band to the DUT 100 through the test antenna 6 and receive a control signal (call connection response signal) transmitted after setting the connection requested frequency by the DUT 100 having received the call connection request signal. By the call connection control, a state in which a radio signal in the first transmission and reception measurement target frequency band can be transmitted and received through the test antenna 6 automatically arranged at the focal position F of the reflector 7 and the reflector 7 is established between the NR system simulator 20 and the DUT 100.

In the DUT 100 after the completion of call connection control, processing for receiving the radio signal transmitted from the NR system simulator 20 through the test antenna 6 and the reflector 7 is downlink (DL) processing, and conversely, processing for transmitting the radio signal to the NR system simulator 20 through the reflector 7 and the test antenna 6 is uplink (UL) processing. The test antenna 6 is used to perform processing for establishing a link (call) and processing of downlink (DL) and uplink (UL) after link establishment, and may be referred to as a link antenna.

After establishing the call connection in step S5, the signal transmission and reception control unit 15 of the integrated control device 10 transmits a signal transmission command to the NR system simulator 20. Based on the signal transmission command, the NR system simulator 20 performs control to transmit a test signal to the DUT 100 through the test antenna 6 automatically arranged at the focal position F of the reflector 7 (step S6).

The test signal transmission control of the NR system simulator 20 is performed as follows. In the NR system simulator 20 (refer to FIG. 4), the control unit 22 that has received the above-described signal transmission command controls the signal generation function unit to generate a signal for generating a test signal in the signal generation unit 21 a. Thereafter, this signal is subjected to digital/analog conversion processing by the DAC 21 b and subjected to modulation processing by the modulation unit 21 c. Then, the RF unit 21 d generates a test signal in which the digitally modulated frequency corresponds to the frequency of each communication standard, and the transmission unit 21 e outputs the test signal (DL data) to the DUT 100 through the test antenna 6. After starting the control of the test signal transmission in step S5, the signal transmission and reception control unit 15 performs control to transmit a test signal at an appropriate timing until the measurement of the transmission and reception characteristics of the DUT 100 in a frequency band corresponding to the test antenna 6 ends. In addition, during this period of time, in the integrated control device 10, the DUT posture control unit 17 continues to control the two-axis positioner 56 a so that the DUT 100 mounted on the DUT mounting unit 56 c has the above-described posture.

On the other hand, the DUT 100 operates such that the test signal (DL data) transmitted through the test antenna 6 and the reflector 7 is received by the antenna 110 in the state of sequentially different postures based on the above-described posture control and the measurement target signal, which is a response signal with respect to the test signal, is transmitted.

After the transmission of the test signal is started in step S6, the signal transmission and reception control unit 15 performs processing causing the test antenna 6, which is automatically arranged at the focal position F of the reflector 7, to receive the measurement target signal that is transmitted from the DUT 100 having received the test signal and reflected by the reflector 7 (step S7).

At the time of the reception processing, the measurement target signal received through the test antenna 6 is input to the signal processing unit 40. The signal processing unit 40 is formed by an up converter, a down converter, an amplifier, a frequency filter, and the like. The signal processing unit 40 performs each processing of frequency conversion (up conversion or down conversion), amplification, and frequency selection on the measurement target signal input from the test antenna 6.

Then, the NR system simulator 20 performs processing for measuring the measurement target signal frequency-converted by the frequency converter (step S8). In this measurement processing, the frequency-converted measurement target signal is input to the reception unit 21 f of the RF unit 21 d in the NR system simulator 20 (refer to FIG. 4).

In the NR system simulator 20, the control unit 22 controls the signal analysis function unit to convert the measurement target signal input to the reception unit 21 f of the RF unit 21 d into an IF signal first. Then, the control unit 22 performs control such that the analog signal is converted into a digital signal by the ADC 21 g and input to the analysis processing unit 21 h and waveform data corresponding to the I component baseband signal and the Q component baseband signal is generated by the analysis processing unit 21 h. In addition, the control unit 22 controls the analysis processing unit 21 h to analyze the measurement target signal based on the generated above-described waveform data.

In the NR system simulator 20, the control unit 22 performs control to measure the transmission and reception characteristics of the DUT 100 based on the analysis result of the measurement target signal by analysis processing unit 21 h (step S8). For example, for the transmission characteristics of the DUT 100, the control unit 22 performs processing for transmitting a Ping request frame as a test signal from the NR system simulator 20 and evaluating the transmission characteristics of the DUT 100 based on a Ping Reply frame transmitted as a measurement target signal from the DUT 100 in response to the Ping request frame. In addition, for the reception characteristics of the DUT 100, the control unit 22 calculates, as an error rate (BER), a ratio between the number of transmissions of the measurement frame transmitted as a test signal from the NR system simulator 20 and the number of receptions of ACK transmitted as a measurement target signal from the DUT 100 in response to the measurement frame. In accordance with the control to measure the transmission and reception characteristics of the DUT 100 in step S8, in the integrated control device 10, for example, the control unit 32 performs control to store the analysis result of the measurement target signal by the NR system simulator 20 in a storage region, such as a RAM (not shown), as transmission and reception characteristics.

Then, in the integrated control device 10, for example, the automatic antenna arrangement control unit 16 determines whether or not the measurement of the transmission and reception characteristics of the DUT 100 has ended for the first measurement target frequency band corresponding to n=1 (step S9). Here, in a case where it is determined that the measurement for the first measurement target frequency band has not ended (NO in step S9), processing from step S6 is continued.

On the other hand, in a case where it is determined that the measurement for the first measurement target frequency band has ended (YES in step S9), the automatic antenna arrangement control unit 16 determines whether or not n has reached n=3 indicating the last measurement target frequency band (out-band 2) (step S10). Here, in a case where it is determined that n has not reached n=3 (NO in step S10), the automatic antenna arrangement control unit 16 proceeds to step S3 to set n to n=2 indicating the second frequency band (out-band 1) (step S3).

Then, using the same method as in the case of n=1, the automatic antenna arrangement control unit 16 performs control to automatically move the test antenna 6, which corresponds to the second measurement target frequency band corresponding to n=2, to the focal position F of the reflector 7 (step S4). Then, the call connection control unit 14 performs call connection control to establish a call between the NR system simulator 20 and the DUT 100 by driving the test antenna 6 newly arranged at the focal position F of the reflector 7 to (step S5).

Thereafter, the integrated control device 10 performs the processing of S6 to S10 (the same as the processing performed according to transmission and reception of the test signal and the measurement target signal by the test antenna 6 corresponding to the first measurement target frequency band) according to transmission and reception of the test signal and the measurement target signal by the test antenna 6 corresponding to the second measurement target frequency band corresponding to n=2.

During this period of time, in the integrated control device 10, the automatic antenna arrangement control unit 16 determines whether or not the measurement of the transmission and reception characteristics of the DUT 100 for the second measurement target frequency band has ended (step S9). Here, in a case where it is determined that the measurement has not ended (NO in step S9), processing from step S6 is continued.

On the other hand, in a case where it is determined that the measurement of the transmission and reception characteristics of the DUT 100 for the second measurement target frequency band has ended (YES in step S9), the automatic antenna arrangement control unit 16 determines whether or not n has reached n=3 (step S10). In a case where it is determined that n has not reached n=3 (NO in step S10), the automatic antenna arrangement control unit 16 proceeds to step S3 to set n to n=3 indicating the third frequency band (out-band 2) (step S3).

Then, using the same method as in the case of n=1 and 2, the automatic antenna arrangement control unit 16 performs control to automatically move the test antenna 6, which corresponds to the third measurement target frequency band corresponding to n=3, to the focal position F of the reflector 7 (step S4). Then, the call connection control unit 14 performs call connection control to establish a call between the NR system simulator 20 and the DUT 100 by driving the test antenna 6 newly arranged at the focal position F of the reflector 7 (step S5).

Thereafter, the integrated control device 10 performs the processing of S6 to S10 (the same as the processing performed according to transmission and reception of the test signal and the measurement target signal by the test antenna 6 corresponding to the first and second measurement target frequency bands) according to transmission and reception of the test signal and the measurement target signal by the test antenna 6 corresponding to the third measurement target frequency band corresponding to n=3.

During this period of time, in the integrated control device 10, the automatic antenna arrangement control unit 16 determines whether or not the measurement of the transmission and reception characteristics of the DUT 100 for the third measurement target frequency band has ended (step S9). Here, in a case where it is determined that the measurement has not ended (NO in step S9), processing from step S6 is continued.

On the other hand, in a case where it is determined that the measurement of the transmission and reception characteristics of the DUT 100 for the third measurement target frequency band has ended (YES in step S9), the integrated control device 10 determines whether or not n has reached n=3 (YES in step S10), and the series of measurement processing described above are ended.

As described above, the measurement apparatus (antenna apparatus) 1 according to the present embodiment includes: the OTA chamber 50 having the internal space 51 that is not influenced by the surrounding radio wave environment; the reflector 7 that is housed in the internal space 51 and has a predetermined paraboloid of revolution, radio signals transmitted or received by the antenna 110 of the DUT 100 being reflected through the paraboloid of revolution; a plurality of test antennas 6 that use radio signals in a plurality of measurement target frequency bands for measuring transmission and reception characteristics of the DUT 100; and the automatic antenna arrangement means 60 for sequentially arranging the plurality of test antennas 6 at the focal position F, which is determined from the paraboloid of revolution, according to the measurement target frequency bands.

With this configuration, in the measurement apparatus 1 according to the present embodiment, the user does not need to perform a work for sequential replacement of the plurality of test antennas 6 at the focal position F of the reflector 7 during the measurement of the transmission and reception characteristics of the DUT 100 using the OTA chamber 50. In addition, since the automatic antenna arrangement means 60 is added after shortening the signal propagation path by providing the reflector 7, this is not a major obstacle for the OTA chamber 50 to be made compact. In addition, since it is possible to measure the transmission and reception characteristics of the DUT 100 for each measurement target frequency band without interruption while reducing the time and effort for arranging each test antenna 6, the efficiency of the measurement processing can be improved.

In the measurement apparatus 1 according to the present embodiment, the antenna 110 of the DUT 100 uses a radio signal in a specified frequency band. Each time one of the plurality of test antennas 6 is arranged at the focal position F of the reflector 7, a test signal is output to the DUT 100 through the test antenna 6 arranged at the focal position F, and a measurement target signal output from the DUT 100 to which the test signal has been input is received by the test antenna 6 arranged at the focal position F. The NR system simulator 20 that measures the transmission and reception characteristics of the DUT 100 for a radio signal in the measurement target frequency band, which is used by the test antenna 6 arranged at the focal position F, based on the received measurement target signal is further provided.

With this configuration, the measurement apparatus 1 according to the present embodiment can smoothly measure the transmission and reception characteristics of the DUT 100, which has the antenna 110 using a radio signal in a specified frequency band, without much time and effort for replacement of the test antenna 6 for frequency bands of a plurality of different frequency band groups in the specified frequency band.

In the measurement apparatus 1 according to the present embodiment, the specified frequency band is a 5G NR band, and each of the plurality of measurement target frequency bands is a frequency band of any one of frequency band groups of a group of n77, n78, and n79, a group of n258 and n257, and a group of n259 that are a plurality of different frequency band groups in the 5G NR band.

With this configuration, the measurement apparatus 1 according to the present embodiment can smoothly measure the transmission and reception characteristics of the DUT (5G wireless terminal), which has the antenna 110 using a radio signal in the 5G NR band, without much time and effort for replacement of the test antenna 6 for a frequency band of any one of frequency band groups of a group of n77, n78, and n79, a group of n258 and n257, and a group of n259.

In the measurement apparatus 1 according to the present embodiment, the automatic antenna arrangement means 60 is configured to include: the antenna holding mechanism 61 in which each test antenna 6 is arranged on the circumference around the rotary shaft 63 in the rotating body 62 that can rotate around the rotary shaft 63 and which is provided in the internal space 51 of the OTA chamber 50 so that the receiving surface of each test antenna 6 passes through the focal position F of the reflector 7 by rotation of the rotating body 62; the power unit 64 having the driving motor 65 for rotationally driving the rotating body 62 through the rotary shaft 63; and the automatic antenna arrangement control unit 16 that controls the driving motor 65 so that each test antenna 6 is sequentially stopped at the focal position F according to the measurement target frequency band.

With this configuration, since the measurement apparatus 1 according to the present embodiment adopts the antenna holding mechanism 61 in which each test antenna 6 is arranged on the circumference around the rotary shaft 63, it is possible to reduce the installation space of the antenna holding mechanism 61 while keeping the OTA chamber 50 compact.

In the measurement apparatus 1 according to the present embodiment, the antenna holding mechanism 61 is provided on the bottom surface 52 a of the internal space 51 of the OTA chamber 50, and is formed by the rotating body 62 that can rotate along a plane in the horizontal direction by the rotary shaft 63 along the vertical direction. With this configuration, in the measurement apparatus 1 according to the present embodiment, a space horizontal to the bottom surface 52 a of the internal space 51 of the OTA chamber 50 is secured as an installation space of the antenna holding mechanism 61. Therefore, it is possible to prevent an increase in the height of the OTA chamber 50.

In the measurement apparatus 1 according to the present embodiment, the antenna holding mechanism 61 holds each test antenna 6 so that the receiving surface of the test antenna 6 is directed to the rotary shaft 63 side. With this configuration, in the measurement apparatus 1 according to the present embodiment, the antenna holding mechanism 61 is arranged at the central portion of the bottom surface 52 a of the internal space 51 of the OTA chamber 50. Therefore, since the diameter of the circumference on which each test antenna 6 is arranged can be reduced, it is possible to keep the antenna holding mechanism 61 and the OTA chamber 50 compact.

In the measurement apparatus 1 according to the present embodiment, in a case where the test antenna 6 is stopped at the focal position F of the reflector 7, the antenna holding mechanism 61 holds the test antenna 6 so as to face the reflector 7 at an angle at which the receiving surface of the test antenna 6 is perpendicular to the beam axis of the radio signal, for example, at an elevation angle of 30°. With this configuration, in the measurement apparatus 1 according to the present embodiment, it is possible to improve the reception accuracy of the test antenna 6 arranged at the focal position F of the reflector 7 and improve the measurement accuracy of the transmission and reception characteristics of the DUT 100.

The measurement method according to the present embodiment is a measurement method using the measurement apparatus 1 having the configuration described above, and includes: a holding step of holding the DUT 100 in the DUT holding unit 56 in the OTA chamber 50 (step S1 in FIG. 10); an antenna arrangement step of sequentially arranging a plurality of test antennas 6 at the focal position F according to the measurement target frequency band based on a predetermined measurement start command (steps S3 and S4 in FIG. 10); a test signal output step of causing the NR system simulator 20 to output a test signal to the DUT 100 through the test antenna 6 arranged at the focal position F (step S6 in FIG. 10); a signal receiving step of receiving a measurement target signal, which is output from the DUT 100 to which the test signal has been input, through the test antenna 6 arranged at the focal position F (step S7 in FIG. 10); and a measurement step of measuring transmission and reception characteristics of the DUT 100 for a radio signal in the measurement target frequency band, which is used by the test antenna 6 arranged at the focal position F, based on the measurement target signal received in the signal receiving step (step S8 in FIG. 10).

With this configuration, in the measurement method according to the present embodiment, since the measurement apparatus (antenna apparatus) 1 having the OTA chamber 50 in which the automatic antenna arrangement means 60 is provided is used, the user does not need to perform a work for sequential replacement of the plurality of test antennas 6 at the focal position F of the reflector 7 during the measurement of the transmission and reception characteristics of the DUT 100. In addition, since the automatic antenna arrangement means 60 is added after shortening the signal propagation path by providing the reflector 7, this is not a major obstacle for the anechoic box to be made compact. In addition, since it is possible to measure the transmission and reception characteristics of the DUT 100 for each measurement target frequency band without interruption while reducing the time and effort for arranging each test antenna 6 at the focal position F, the efficiency of the measurement processing can be improved.

Second Embodiment

As shown in FIG. 11, in a measurement apparatus 1A according to a second embodiment of the present invention, an OTA chamber 50A adopting automatic antenna arrangement means 60A is used instead of the OTA chamber 50 used in the measurement apparatus 1 according to the first embodiment. In the automatic antenna arrangement means 60A, the same components as the automatic antenna arrangement means 60 (refer to FIGS. 1 and 2) mounted in the OTA chamber 50 according to the first embodiment are denoted by the same reference numerals.

As shown in FIG. 11, similarly to the automatic antenna arrangement means 60 according to the first embodiment, the automatic antenna arrangement means 60A according to the present embodiment has: an antenna holding mechanism 61 in which each test antenna 6 is arranged on the circumference around a rotary shaft 63 in a rotating body 62 that can rotate around the rotary shaft 63 and which is provided in the internal space of the OTA chamber 50A so that the receiving surface of each test antenna 6 passes through the focal position F of a reflector 7 by rotation of the rotating body 62; and a power unit 64 having a driving motor 65 for rotationally driving the rotating body 62 through the rotary shaft 63. That is, also in the automatic antenna arrangement means 60A according to the present embodiment, the antenna holding mechanism 61 is provided on the bottom surface of the internal space 51 of the OTA chamber 50A, and is formed by the rotating body 62 that can rotate along a plane in the horizontal direction by the rotary shaft 63 along the vertical direction.

The automatic antenna arrangement means 60A according to the present embodiment has the same configuration as the automatic antenna arrangement means 60 according to the first embodiment except for the arrangement of the test antenna 6 with respect to the rotating body 62. In the automatic antenna arrangement means 60 according to the first embodiment, the antenna holding mechanism 61 holds each test antenna 6 so that the receiving surface of each test antenna 6 is directed to the rotary shaft 63 side (inner side) (refer to FIG. 1). In contrast, in the automatic antenna arrangement means 60A according to the present embodiment, as shown in FIG. 11, the antenna holding mechanism 61 holds each test antenna 6 so that the receiving surface of each test antenna 6 is directed to the opposite side (outer side) to the rotary shaft 63 side.

Also in the automatic antenna arrangement means 60A according to the present embodiment, the driving motor 65 forming the power unit 64 is connected to the automatic antenna arrangement control unit 16. In addition, also in the present embodiment, the automatic antenna arrangement control table 16 a is prepared in advance in which the number of operation pulses (here, a value different from that in the first embodiment) that can be arranged at the focal position F of the reflector 7 corresponding to each test antenna 6 is stored. Therefore, also in the measurement apparatus 1A according to the present embodiment, as in the first embodiment, the automatic antenna arrangement control unit 16 reads the number of operation pulses of each test antenna 6 from the automatic antenna arrangement control table 16 a and controls the rotation of the driving motor 65 based on the number of pulses, along the flowchart shown in FIG. 10, so that each test antenna 6 can be sequentially arranged at the focal position F of the reflector 7 (refer to step S4 in FIG. 10).

In the measurement apparatus (antenna apparatus) 1A according to the present embodiment, the automatic antenna arrangement means 60A for automatically arranging the test antenna 6 at the focal position F of the reflector 7 in a sequential manner. Therefore, as in the first embodiment, it is possible to easily measure the transmission and reception characteristics of the DUT 100 without forcing the user to perform a work for replacement of the plurality of test antennas 6. In particular, according to the configuration of the OTA chamber 50A having the automatic antenna arrangement means 60A according to the present embodiment, for example, the antenna holding mechanism 61A is arranged at a position avoiding the central portion of the bottom surface 52 a of the internal space 51. Therefore, the diameter of the circumference on which the test antenna 6 is arranged is reduced. This is useful for making the antenna holding mechanism 61A small.

Third Embodiment

As shown in FIGS. 12A and 12B, in a measurement apparatus 1B according to a third embodiment of the present invention, an OTA chamber 50B adopting automatic antenna arrangement means 60B is used instead of the OTA chambers 50 and 50A used in the measurement apparatuses 1 and 1A according to the first and second embodiments. FIG. 12A shows a schematic configuration viewed from the front of the automatic antenna arrangement means 60B, and FIG. 12B shows a schematic configuration of the automatic antenna arrangement means 60B viewed from the right side of FIG. 12A.

The automatic antenna arrangement means 60 and 60A of the measurement apparatuses 1 and 1A according to the first and second embodiments has the antenna holding mechanism 61 that holds a plurality of test antennas 6 on the circumference of the rotating body 62 that can rotate on the horizontal plane through the rotary shaft 63 perpendicular to the horizontal plane. In contrast, as shown in FIGS. 12A and 12B, the automatic antenna arrangement means 60B according to the present embodiment has an antenna holding mechanism 61B that holds a plurality of test antennas 6 on the circumference along the outer periphery of a rotating body 62B that can rotate along a plane in the vertical direction through a rotary shaft 63B extending in the horizontal direction. A power unit 64B of the automatic antenna arrangement means 60B is formed by the same driving motor 65B as the driving motor 65 according to the first and second embodiments and a connection member 66B interposed between the driving motor 65B and the rotary shaft 63B of the rotating body 62B.

The automatic antenna arrangement means 60B according to the present embodiment is different from the first and second embodiments in that the plurality of test antennas 6 held by the antenna holding mechanism 61B rotate along the plane in the vertical direction with rotation of the rotating body 62B. However, the automatic antenna arrangement means 60B according to the present embodiment is the same as the first and second embodiments in that the movement of each test antenna 6 to a predetermined position on the circumference, in particular, the focal position F of the reflector 7 can be controlled by the amount of rotation of the driving motor 65B, that is, the number of driving pulses applied to the driving motor 65B.

Therefore, also in the present embodiment, the automatic antenna arrangement control table 16 a is prepared in advance in which the number of operation pulses (here, a value different from those in the first and second embodiments) that can be arranged at the focal position F of the reflector 7 corresponding to each test antenna 6 is stored. Then, in the automatic antenna arrangement control unit 16 to which the driving motor 65B forming the power unit 64B of the automatic antenna arrangement means 60B is connected, driving control of the driving motor 65B is performed based on the automatic antenna arrangement control table 16 a. In this case, the automatic antenna arrangement control unit 16 reads the number of operation pulses of each test antenna 6 from the automatic antenna arrangement control table 16 a and controls the rotation of the driving motor 65B based on the number of pulses, so that each test antenna 6 can be sequentially arranged at the focal position F of the reflector 7 (refer to step S4 in FIG. 10).

In the measurement apparatus (antenna apparatus) 1B according to the present embodiment, the automatic antenna arrangement means 60B for automatically arranging the test antenna 6 at the focal position F of the reflector 7 in a sequential manner. Therefore, as in the first embodiment, it is possible to easily measure the transmission and reception characteristics of the DUT 100 without forcing the user to perform a work for replacement of the plurality of test antennas 6. In particular, according to the configuration of the OTA chamber 50B having the automatic antenna arrangement means 60B according to the present embodiment, a space perpendicular to the bottom surface 52 a of the internal space 51 can be secured as an installation space of the antenna holding mechanism 61B. Therefore, it is possible to prevent an increase in the width of the housing main body 52.

Fourth Embodiment

As shown in FIG. 13, in a measurement apparatus 1C according to a fourth embodiment of the present invention, an OTA chamber 50C adopting automatic antenna arrangement means 80 is used instead of the OTA chamber 50 used in the measurement apparatus 1 according to the first embodiment. In the present embodiment, an example has been mentioned in which the automatic antenna arrangement means 80 automatically arranges the nine test antennas 6 that can use different measurement target frequency bands. However, it is needless to say that the present invention can also be applied to a case where the three test antennas 6 exemplified in the first to third embodiments as will be described below.

As shown in FIG. 13, the automatic antenna arrangement means 80 according to the present embodiment has an antenna holding mechanism 81 and a power unit 87. The antenna holding mechanism 81 is formed by a plurality of first slide mechanisms 81 a, 81 b, and 81 c and a second slide mechanism 84 arranged perpendicular to the first slide mechanisms 81 a, 81 b, and 81 c. Each of the first slide mechanisms 81 a, 81 b, and 81 c has a plurality of antenna pedestals 82, and is configured to hold the antenna pedestals 82 so as to be slidable in one direction while maintaining a predetermined interval along a pair of guide rails 83, for example. Here, the one direction is, for example, a Y axis direction on a plane formed by an X axis and a Y axis perpendicular to each other. The test antenna 6 is attached to each of the antenna pedestals 82.

In FIG. 13, the configuration in which the nine test antennas 6 attached to the nine antenna pedestals 82 are automatically arranged at the focal position F is illustrated. However, the automatic antenna arrangement means 80 can respond to the automatic arrangement of any number of test antennas 6 by changing or modifying the configuration. For example, in order for the automatic antenna arrangement means 80 to automatically arrange the three test antennas 6 as in the first to third embodiments, each test antenna 6 may be provided on three antenna pedestals 82 in FIG. 13. In addition, by configuring the automatic antenna arrangement means 80 shown in FIG. 13 such that only one first slide mechanism (for example, 81 a) is provided or only the second slide mechanism 84 is provided, it is possible to respond to the automatic arrangement of the three test antennas 6.

On the other hand, the second slide mechanism 84 has a pedestal portion 85 on which the first slide mechanisms 81 a, 81 b, and 81 c are mounted, and holds the first slide mechanisms 81 a, 81 b, and 81 c so as to be slidable in the other direction perpendicular to the Y axis direction along a pair of guide rails 86, for example.

The power unit 87 has driving shafts 87 a, 87 b, and 87 c, which are provided along the Y axis direction so as to pass through a through hole 82 a of the antenna pedestal 82 forming each of the first slide mechanisms 81 a, 81 b, and 81 c, and first driving motors 88 a, 88 b, and 88 c for rotationally driving the driving shafts 87 a, 87 b, and 87 c. In addition, the power unit 87 has a driving shaft 89 a, which is provided along the X axis direction so as to pass through a through hole 85 a of the pedestal portion 85 forming the second slide mechanism 84, and a second driving motor 89 b for rotationally driving the driving shafts 89 a. In the through hole 82 a of each antenna pedestal 82 described above and the through hole 85 a of each pedestal portion 85, screws fitted to screws formed on the driving shafts 87 a, 87 b, and 87 c and the driving shaft 89 a are formed. Therefore, the power unit 87 can move each antenna pedestal 82 in both directions corresponding to the forward and reverse rotation directions along the Y axis by rotationally driving the first driving motors 88 a, 88 b, and 88 c in both forward and reverse directions to rotationally drive the driving shafts 87 a, 87 b, and 87 c in the same direction. Similarly, it is possible to move each pedestal portion 85 in both directions corresponding to the forward and reverse rotation directions along the X axis by rotationally driving the second driving motor 89 b in both forward and reverse directions to rotationally drive the driving shaft 89 a in the same direction.

In the automatic antenna arrangement means 80 shown in FIG. 13, the antenna holding mechanism 81 is provided on, for example, the bottom surface 52 a in the internal space 51 of the OTA chamber 50C so that each test antenna 6 mounted on each antenna pedestal 82 can pass through the focal position F of the reflector 7. In the configuration shown in FIG. 13, the focal position F of the reflector 7 can be expressed by the coordinates on the XY plane. The amount of movement of the pedestal portion 85 in the X axis direction corresponds to the number of operation pulses of the second driving motor 89 b, and the amount of movement of the antenna pedestal 82 in the Y axis direction corresponds to the number of operation pulses of the first driving motors 88 a, 88 b, and 88 c.

Based on such conditions, in the measurement apparatus 1C according to the present embodiment, as the automatic antenna arrangement control table 16 a, the number of operation pulses of the second driving motor 89 b and the number of operation pulses of the first driving motors 88 a, 88 b, and 88 c that can be arranged at the focal position F of the reflector 7 corresponding to each test antenna 6 are stored as control data. Therefore, in the automatic antenna arrangement control unit 16, it is possible to control the driving of the first driving motors 88 a, 88 b, and 88 c and the second driving motor 89 b based on the automatic antenna arrangement control table 16 a. In this driving control, the automatic antenna arrangement control unit 16 reads the number of operation pulses of the second driving motor 89 b and the number of operation pulses of the first driving motors 88 a, 88 b, and 88 c corresponding to each test antenna 6 from the automatic antenna arrangement control table 16 a and controls the rotation of the first driving motors 88 a, 88 b, and 88 c and the second driving motor 89 b based on the number of pulses, so that each test antenna 6 can be sequentially arranged at the focal position F of the reflector 7 (refer to step S4 in FIG. 10).

In the measurement apparatus (antenna apparatus) 1C according to the present embodiment, the automatic antenna arrangement means 80 for automatically arranging the test antenna 6 at the focal position F of the reflector 7 in a sequential manner is provided on the XY plane. Therefore, as in the first to third embodiments, it is possible to easily measure the transmission and reception characteristics of the DUT 100 without forcing the user to perform a work for replacement of the plurality of test antennas 6. In particular, according to the configuration of the OTA chamber 50C having the automatic antenna arrangement means 80 according to the present embodiment, a space horizontal to the bottom surface 52 a of the internal space 51 of the OTA chamber 50C is secured as an installation space of the antenna holding mechanism 81. Therefore, it is possible to prevent structural expansion of the OTA chamber 50C (housing main body 52) in the height direction. In addition, since the test antennas 6 slide in directions perpendicular to each other on the horizontal plane, stable movement of the reflector 7 toward the focal position F is possible.

In the measurement apparatus 1C according to the present embodiment, a plurality of first slide mechanisms 81 a, 81 b, and 81 c are provided so as to be parallel to the Y axis direction and be spaced apart from each other by a predetermined distance in the X axis direction, and the power unit 87 is configured to include the first driving motors 88 a, 88 b, and 88 c corresponding to the first slide mechanisms 81 a, 81 b, and 81 c. With this configuration, the measurement apparatus 1 can easily cope with the addition of the test antenna 6 while avoiding an increase in the size of the OTA chamber 50C by making full use of the space in the horizontal direction on the bottom surface 52 a of the housing main body 52 of the OTA chamber 50C. In the present embodiment, a plurality of first slide mechanisms and a plurality of first driving motors do not necessarily need to be provided, and one first slide mechanism and one first driving motor may be provided.

In each of the embodiments described above, an example has been mentioned in which the measurement of the transmission and reception characteristics of the DUT 100 in three bands (refer to FIG. 8) in the 5G NR band are covered with, for example, three test antennas 6 (up to nine in the fourth embodiment). However, the present invention is not limited thereto, and the transmission and reception characteristics of the DUT 100 for a plurality of bands in the 5G NR band may be measured using any number of test antennas 6. In addition, the means 60, 60A, 60B, and 60C for automatically arranging the test antenna 6 is not limited to that described in each of the above embodiments, and it is needless to say that various modes including means for manually arranging the test antenna 6 can be applied. In addition, the present invention can be applied not only to the anechoic box but also to the anechoic chamber.

As described above, the antenna apparatus and the measurement method according to the present invention have an effect that the transmission and reception characteristics for frequency bands corresponding to a plurality of test antennas of the DUT can be efficiently measured while avoiding an increase in the size of the anechoic box and the complication of the work for replacement of the test antenna. This is useful for all kinds of antenna apparatuses and measurement methods for performing transmission and reception measurement of wireless terminals capable of using the 5G NR band.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

-   -   1, 1A, 1B, 1C: measurement apparatus (antenna apparatus)     -   6: test antenna (antenna)     -   7: reflector     -   10: integrated control device     -   16: automatic antenna arrangement control unit     -   20: NR system simulator (simulation measurement device)     -   30: signal analysis device     -   40: signal processing unit     -   50: OTA chamber (anechoic box)     -   51: internal space     -   60, 60A, 60B: automatic antenna arrangement means (antenna         arrangement means)     -   61, 61B: antenna holding mechanism     -   62, 62B: rotating body     -   63, 63B: rotary shaft     -   64, 64B: power unit     -   65, 65B: driving motor     -   80: automatic antenna arrangement means     -   81: antenna holding mechanism     -   81 a, 81 b, 81 c: first slide mechanism     -   82: antenna pedestal     -   84: second slide mechanism     -   85: pedestal portion     -   87: power unit     -   87 a, 87 b, 87 c: first driving shaft     -   88 a, 88 b, 88 c: first driving motor     -   89 a: second driving shaft     -   89 b: second driving motor     -   100: DUT (device under test)     -   110: antenna (antenna to be tested)     -   F: focal position of reflector 

What is claimed is:
 1. An antenna apparatus, comprising: an anechoic box having an internal space that is not influenced by a surrounding radio wave environment; a reflector that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna to be tested of a device under test being reflected through the paraboloid of revolution; a plurality of antennas corresponding to radio signals in a plurality of measurement target frequency bands for measuring transmission and reception characteristics of the device under test; and antenna arrangement means configured to sequentially change an arrangement of the plurality of antennas at a focal position, which is determined from the paraboloid of revolution, according to the measurement target frequency bands.
 2. The antenna apparatus according to claim 1, wherein the antenna to be tested uses a radio signal in a specified frequency band, and a simulation measurement apparatus is further provided that, each time one of the plurality of antennas is arranged at the focal position, outputs a test signal to the device under test through the antenna arranged at the focal position, receives a measurement target signal output from the device under test to which the test signal has been input through the antenna arranged at the focal position, and measures transmission and reception characteristics of the device under test for the measurement target frequency band, which is used by the antenna arranged at the focal position, based on the received measurement target signal.
 3. The antenna apparatus according to claim 2, wherein the specified frequency band is a 5G NR (New Radio) band, and each of the plurality of measurement target frequency bands is a frequency band of any one of frequency band groups of a group of n77, n78, and n79, a group of n258 and n257, and a group of n259 that are a plurality of different frequency band groups in the specified frequency band.
 4. The antenna apparatus according to claim 1, wherein the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.
 5. The antenna apparatus according to claim 4, wherein the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a horizontal direction by the rotary shaft along a vertical direction.
 6. The antenna apparatus according to claim 4, wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.
 7. The antenna apparatus according to claim 4, wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.
 8. The antenna apparatus according to claim 4, wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
 9. The antenna apparatus according to claim 2, wherein an antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a vertical direction by the rotary shaft along a horizontal direction.
 10. The antenna apparatus according to claim 1, wherein the antenna arrangement means includes: an antenna holding mechanism that has a first slide mechanism that holds a plurality of antenna pedestals, on which the antennas are provided, so as to be slidable in one direction while maintaining a predetermined interval and a second slide mechanism that slidably holds the first slide mechanism in the other direction perpendicular to the one direction through a pedestal portion and that is provided in the internal space of the anechoic box such that each of the antennas is able to pass through the focal position; a power unit that includes a first driving motor for rotationally driving a first driving shaft for sliding each of the antenna pedestals in the one direction and a second driving motor for rotationally driving a second driving shaft for sliding the pedestal portion in the other direction; and an automatic antenna arrangement control unit that controls the first and second driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.
 11. The antenna apparatus according to claim 10, wherein a plurality of the first slide mechanisms are provided so as to be parallel to the one direction and be spaced apart from each other by a predetermined distance in the other direction, and the power unit includes the first driving motor corresponding to each of the first slide mechanisms.
 12. The antenna apparatus according to claim 2, wherein the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.
 13. The antenna apparatus according to claim 3, wherein the antenna arrangement means operates automatically, and includes: an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body; a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the measurement target frequency bands.
 14. The antenna apparatus according to claim 5, wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.
 15. The antenna apparatus according to claim 5, wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.
 16. The antenna apparatus according to claim 5, wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
 17. The antenna apparatus according to claim 6, wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
 18. The antenna apparatus according to claim 7, wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
 19. The antenna apparatus according to claim 3, wherein the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a vertical direction by the rotary shaft along a horizontal direction.
 20. A measurement method using an antenna apparatus that includes an anechoic box having an internal space that is not influenced by a surrounding radio wave environment, a reflector that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna to be tested of a device under test being reflected through the paraboloid of revolution, a plurality of antennas corresponding to radio signals in a plurality of measurement target frequency bands for measuring transmission and reception characteristics of the device under test, and antenna arrangement means for sequentially arranging the plurality of antennas at a focal position, which is determined from the paraboloid of revolution, according to the measurement target frequency bands, the method comprising: a holding step of holding the device under test in a device under test holding unit in the anechoic box; an antenna arrangement step of sequentially arranging the plurality of antennas at the focal position according to the measurement target frequency bands based on a predetermined measurement start command; a test signal output step of causing a simulation measurement device to output a test signal to the device under test through the antenna arranged at the focal position; a signal receiving step of receiving a measurement target signal, which is output from the device under test to which the test signal has been input, through the antenna arranged at the focal position; and a measurement step of measuring transmission and reception characteristics of the device under test for a radio signal in the measurement target frequency band, which is used by the antenna arranged at the focal position, based on the measurement target signal received in the signal receiving step. 